Power supply and truck: what they have in common

1. Step 1. Power supply — has part — Transformer. A transformer.
2. Step 2. Transformer — is part of — Defibrillator. Stepping up the voltage.
3. Step 3. Defibrillator — is part of — Ambulance. A defibrillator.
4. Step 4. Ambulance — evolved from — Truck. A special-purpose vehicle.

Open Evothings